Current-distributing network.



G, WOLFE CURRENT DISTRIBUTING NETWORK.

APPLICATION FLLEQ OCT. 1 1912. 1 ,OQB QQAL Patented. May 26, 191% 3 8HEETS-SHEET 1.

G. WOLFE.

CURRENT DISTRIBUTING NETWORKw AFPLTUATION Y'ILBD 0011,1912.-

1,098,204, Patented May 26, 1914.

3 SHEETSSHEET 2.

G. WOLFE. I CURRENT mswmumw NETWORK.

- APPLICATION FILED 0GT.1,1912. 1,098,204, Patented May 28, 1914.;

3 SHEETS-SHEET 3.

' w iii;

UNITllil'l dill oF C

ELEKrRIorrACrs-umnnu, AKTTEEHGESELLSUHAFT,

GERMANY, .E. CDRPUREJJLION.

3]? HEBMSDORF, NEAR BERLIN,

GURRENT-DISTIEt-IBUTXNG N E'll fi 0331K.

.Spccificatiou of llettel's Patent.

Petenteu may 26, 1914:.

I Implication filed October 1, 1912. serial No. ?23,37 l.

. To all '10 item it may concern Be it known that l, Geo 3'. our; subject of the German Emperor, and residing at Hennsdorf, near Berlin, Germany, have invented certain new and useiul Improvements in Current-Distrihuting il e morlr of which the following is a specification.

My invention relates to a current distribuh ing network, consisting of main conductors, auxiliary conductors and devices to separate the main conductors automatically in sections from one another, as soon as a faultin the insulation occurs.

The desired object is attained by arrangements, consisting of several separate main conductor sections, running parallel. to these, also separate, auxiliary conductor sections insulated from the earth, switches for connecting the main conductor sections at their ends, and means by which. the switches at both ends of the corresponding. nrain coir ductor section are automatically opened us soon as through a fault in the insulation the neutral point is displaced in relation to the auxiliary conductor section.

In the drawings herewith,

Figure 1. is a diagrammatic cross section througha thin-c core three phase cable such as may be our ployed in my invention; Figs. 2 andl3 are cross sections of slightly difi'crent forms of cable; Fig. t is a diagram showing how the cores of such cable may be connected to the auxiliary conductor; Fig. 5 shows a. vertical section and a plan View of the potential relay employed; and Figs. (3, '1' and 8 are diagrams of slight modifications as hereinafter explained.

The appended Figs. 1 to 5 explain the invention for instance in reference to it high tension, three-core, three phase cable. The cross section through the cable in Fig. 1 shows the three main cores a a, and a which With insulating material in betw en are surrounded by sheaths h, constituting the auxiliary conductor, these sheaths being electrically interconnected. As long as the cable is intact the auxiliary conductor h then forms the neutral point of a three phase system. and three voltinetes r 1 and 11 connected between it and the three cores a a a direct or through a three phase potential transformer, will show the some readings. If, however, a. fault develops in the cable the symmetry of the system Will he at once destroyed and the readings of the roltineters will dil'ler.

The form of auxiliary conductor shown in Fig. 1 can. be made by pressing a metal sheath around the cores, or by lapping them Withmetal tape, or in some similar manner, but. this method does not affect the main idea of the invention. Thus, for instance, Fig. 2 shows an auxiliary conductor which is split upinto a number of single parallel Wires (Z placed around and in between the main conductors, and Fig. 3 shows cores a,

a and a iucloscd in a sheath m and a cenblill conductor n Which form either individually or combined the-auxiliary conductor, but these examples do not exhaust, 111

any Way, the diiierent methods of'forming the an.

iis section of three phase cable, the three main cores (11,, 1,, ere connected to theeuxiliary condmztor fl through the primary windings ial transformers 25,, and to the I windings of which the-three phase potential relays *1, and T are connected. long as the cable section is intact and the auxiliary conductor forms the neutral point of the three phase system, the three forces working on each relay are equal and in perfeet equilibrium. This equilibrium, however is upset as soon as through a short circuit or a fault to earth in the cable, the auxiliary conductor loses its property as the neutral. point, and the consequence is that the contacts 7c, and 70 of the relays close, Wherebythe current of the auxiliary batteries b and or current from any other source acts onthe release coils s and s and liar-y conductor.

own in Fig. 4: at both ends of the trips the latches l, 1 of the switches 0 and nected at the ends of the cable and further connectml with the neutral points of the respective potential relays o, and "v The forces of both coils of eachrelay neutralize one another as long as the cables are lntact,

but, on the other hand, on a fault developing in. one cable the torque of one relay coil will exceed that of the other and contact will then be made at is, and k with the iii g g. I 1,098

effect that in the same way as described in F l the cable sections are then disconnected by switches 0 and 0 'lhese safety devices are also suitable for overhead networks for disconnecting any section, should the insulators break down, the auxiliary conductor being connected electrically with the insulator supports. in this case, in order that this arrangement may work con iectly, the essential insulation of tho auxiliary conductor from ground may be obtaincd 'by insulating the insulator supports from the poles, unless wooden poles he used and the insulating quality of the wood be suhcicnt for this purpose.

Fig. 5 shows diagranunatically the'construction of a three-pole potential relay, such as would be used for protecting a. three phase line. A three-armed armature c is arranged above the phase coils c, c. which is held. in equilibrium when the tongue of the coils equal, but which is tilted as soon as the power of one or two coils exceeds that of the other or others, thus closi' one ot' the auxiliary contacts and. thc-rc..)y causing" thc switch to open. should a short circuit take place simultancmisly .ietwcen all three 1' it could, houercr, happen t Kill? the i l differences between. all three phases and the auxiliary conductor may sink to Zero and the relay coils would then exert no power on the armature at all and in spite ol the fault in the cable no contact would. be made 2'. ln order to prevent this, the relay can he providcd with a spring wlfch pm s the three-armed armatme against contacts 2' thereby closing them as soon the torque of the coils completely disappears. however, the s ring f would also act and close the contacts 2', should, at times thero'ltagc in the power station cli.:-;appcar,

and asin such. a case the disconnection of any cal le sections would not he desirable, the clo g, of the auxiliary circuit for the automatic release can be made'dependent u the presence of a current in the main 7 c'ther by using as a source of current leasingcurreni'; the secondary "windings of current transformers in the or." 1 condr put circuit by means of current relays u'iliuenced by the current in the main conductors, as soon as the current disappears in the main conductors tliirou rh the voltage in the cc.

Fig.5. 7 shows C'Ul 'cnt transformers W lv' and ll, connected i u the main conductors, the secondaries of these current transtorim crs heir connected with a release coil S so that w li. contact ioiats /l: are closed the oils will not h on ll unless current is rowing in too ma. 1 c 01's. The secmi deiice above to is shown in hi; 8, where the so m in and m )1, or by opening the releasingare connected in series with the main co ductors, these solenoids normally holdii the arnwtures in an elevated position, so

to close the circuit tl'iroug'h releasing coil and a. local battery 1 lVhen current flowing in at least one of the luaincondu tors it obyions that the circuit tl'll'()l] the magnet 55 will be complete.

1. A cable made in. sections, each compri inga plurality of main cores and an auxi iarv conductor constituting the neutral poi of the section; combinedwith main coils r spcetivcly connected with said cores and 1 connected with said auxiliary conductor, oudary coils respectivelyparallel with sa main coils, and instrumcntalities several CODDOClGtl with said secondary coils.

2. A cable made in sections, each coinpri ing a plurality of main cores and a pluralil of wires interconnected at the ends of tl section and constituting an auxiliary co] ducter, the latter constituting the neutr. point of the section; combined with leaf coils respectively connected at one end wit shill cores and all connected at their othe ends with said auxiliary conductor, so ondary coils respectively parallel with sai main coils, and instrumentalitics several] c muccte l with said secondary coils.

A. cable made in sections, each con a. plurality 0? main cores and a p11 rality of wires interconnected at the ends the section and constituting an auxiliary coi ductor, the latter constituting-the neutr; point of the section; combined with mai coils respectively connected at one end wit said cores and all connected at their otlu ends with sai auxiliary conductor, sccont ary coils respectively parallel with said inai coils, switches between the sections, an sa'it l'1-(')} )QI1ing mechanism actuated by nt generated in any secondary coil.

A cable made in sections, each cempri: ing a plurality of main cores and an auxi iary conductorconstituting the neutral poir of the section; combined with main coils l'l spectively connected with said cores and a connected with said auxiliary conductor, se ondary coils respectively parallel with sai main coils, switches between the section: devices for opening each switch, electricall operated mechanism for actuating said dc vices, a circuit closer in the circuit of suc.

mechanism, and ineans for closing the on cuit closer by a current generated in an secondary coil.

A cable made in sections, each compris ing a plurality of main cores and an auiril iary conductor constituting the neutral poin of the section; (JOITI OlIIQLl with main coils re spec'tively connected with said cores and a] connected with said auxiliary conductor coils respectively parallel will main coils, switches between the sec 1,098,204 t I v tions, a latch for opening each switch, a coil for actuating the latch, a motive circuit for this coil, and a circuit closer in such circuit actuated by a current generated in any secondary coil. i

6. A cable made in sections, eachoompris: ing a plurality of main cores and an auxiliary conductor constituting the neutral point of the section; combined with main coils-respectively connected with 'said cores and all connected with said auxiliary conductor, secondary coils respectively parallel with said main coils, switches between sections, a latch for each switch,- a relay circuit having a coil :to'r actuating said latch, anopen relay circuit, and means for closing it by a. current generated in any secondary coil.

7 A cable made in sections, each-compris ing a plurality of main cores and an auxiliary conductor constituting the neutral point of the sectionqcombined with a' potential transformer whose primary coils are connccted with the main cores respectively and with said neutral point, potential relays connected with the secondary coils of said transformer a switch connectin each two cable sections, and" means Ior opening the same by the closing-of the contacts in any relay.

- .8. A three core, three phase cable made in 4 sections, an auxiliary conductor extending alongeach section, and a three-part switch connecting the respective cores between contiguous sections; combined Witha potential transformer whose primary windings are connected respectively to the cores and collectively ,to the auxiliary conductor, three phase potential relays connected with the secondary windings of said transformer, and means for opening the switch by the closing of the contacts in any relay.

'9. A three core, three phase cable made in sections, an auxiliary conductor extending along each section, and a three-part switch connecting the respective cores between contiguous sections; combined with apotential transformer whose primary windings are connected,respectively to the cores and collectiyely to theauxiliary conductor, three-phase potential relays Whose coils are connected with the secondary windings of said transformer a three-armed armature whose arms overlie said coils respectively, a relay circuit closed by the rise of any arm, and means actuated by the coils of the relay circuit for opening said switch;

Intestimonywhereof I alfix my signature in presence of two witnesses.

H GEORG WOLFE. Witnesses: r I,

HENRY HAsrEn, WoLnnMAn Hanrr. 

